<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Weather Data Selection</title>
    <style>
        body {
            font-family: 'Arial', sans-serif;
            background-color: #f4f4f9;
            color: #333;
            line-height: 1.6;
            padding: 20px;
            margin: 0;
        }
        h1 {
            color: #333;
            text-align: center;
            margin-bottom: 20px;
        }
        p {
            max-width: 600px;
            margin: auto;
            margin-bottom: 20px;
        }
        ul {
            list-style: none;
            padding: 0;
        }
        li {
            background-color: #fff;
            border: 1px solid #ddd;
            margin-bottom: 10px;
            padding: 10px;
            border-radius: 5px;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
        }
        li strong {
            display: block;
            color: #007BFF;
            margin-bottom: 5px;
        }
        li ul {
            padding: 0;
            margin-top: 10px;
        }
        li ul li {
            padding: 5px 0;
            border-bottom: 1px solid #eee;
        }
        li ul li:last-child {
            border-bottom: none;
        }
        li ul li a {
            color: #007BFF;
            text-decoration: none;
        }
        li ul li a:hover {
            text-decoration: underline;
        }
    </style>
</head>
<body>
    <h1>Weather Data Selection</h1>
    <p>Welcome to the weather data visualization page. Choose a city to view its weather data or temperature variation.</p>
    <ul>
        {% for city in cities %}
        <li>
            <strong>{{ city }}</strong>
            <ul>
                <li><a href="{{ url_for('city_weather', city=city) }}">View Weather Data</a></li>
                <li><a href="{{ url_for('city_temperature', city=city) }}">View Temperature Variation</a></li>
            </ul>
        </li>
        {% endfor %}
    </ul>
</body>
</html>